Staged bilateral total knee replacement--a safer approach in older patients.

Simultaneous bilateral total knee replacement has been advocated for bilateral symptomatic arthritis of the knee. The alternative is staged bilateral total knee replacement. We retrospectively reviewed all the total knee replacements performed in our hospital between January 1996 and July 1999. A total of 455 patients had 533 total knee replacements: 54 patients had simultaneous bilateral total knee replacement, 34 patients had staged bilateral total knee replacement and 367 patients had unilateral total knee replacements. Four patients who had simultaneous bilateral total knee replacement died in the immediate post-operative period. During the same period, no deaths were observed in the other two groups. Risk factors were assessed and in our series, age was the only factor found to be associated with mortality following simultaneous bilateral total knee replacement. A staged operation appears to be safer than simultaneous bilateral total knee replacement for patients who are 75 years or older.